Hair Cuttery / she cut too much

Don’t visit the place under the name www.haircuttery.com. I arrived on Monday there and told the hairdresser that I wanted to cut a little bit. I told about 3 inches, but the hairdresser cut 6 and it was too short. I was shocked and wanted to cry. How did she do it? Why did she ignore what I have told her? I will never again use the services of this hairdresser.